Gender Differences in Use of Prolonged Nonoperative Therapies Before Index Lumbar Surgery

Objective: The purpose of the present study was to assess for gender-based differences in the usage and cost of maximal nonoperative therapy before spinal fusion surgery in patients with symptomatic lumbar stenosis or spondylolisthesis. Methods: A large insurance database was queried for patients with symptomatic lumbar stenosis or spondylolisthesis undergoing index lumbar decompression and fusion procedures from 2007 to 2016. This database consists of 20.9 million covered lives and includes private or commercially insured and Medicare Advantage beneficiaries. Only patients continuously active within the Humana insurance system for ≥5 years before the index operation were eligible. Usage was characterized by the cost billed to the patient, prescriptions written, and number of units billed. Results: A total of 4133 patients (58.5% women) underwent 1-, 2-, or 3-level posterior lumbar instrumented fusion. A significantly greater percentage of female patients used nonsteroidal anti-inflammatory drugs (P < 0.0001), lumbar epidural steroid injections (P = 0.0044), physical and/or occupational therapy (P < 0.0001), and muscle relaxants (P < 0.0001). The total direct cost associated with all maximal nonoperative therapy before index spinal fusion was $9,000,968, with men spending $3,451,479 ($2011.35 per patient) and women spending $5,549,489 ($2296.02 per patient). When considering the quantity of units billed, women used 61.5% of the medical therapy units disbursed despite constituting 58.5% of the cohort. When normalized by the number of pills billed per patient using therapy, female patients used more nonsteroidal anti-inflammatory drugs, opioids, and muscle relaxants. Conclusions: These results suggest that gender differences exist in the use of nonoperative therapies for symptomatic lumbar stenosis or spondylolisthesis before fusion surgery.